If record data data should be written by an operator's wrong key operation in the electronic memory device, the subsequent processing of data read out from the memory device can not provide a correct result. Prior to the operation of a data-processing device, therefore, it is necessary to collate data previously written in an electronic memory device by key operation with data subsequently entered similarly by key operation in order to confirm whether initial input data was correctly written. Where, however, a large amount of input data is to be handled, it sometimes happens that input data supplied by way of collation does not exactly correspond to the data previously entered. Further, omission of checking tends to take place with a memory cassette or memory file in which unconfirmed data is stored. Therefore, record data whose collation was neglected leads to unreliable processing results when subsequently handled by a data-processing device. Moreover, it is accompanied with a complicated process to examine the correct entry of all data by the subsequent key operation for collation.